Hey- I know it's a late reply, but I just wanted to thank you for giving me a reason to google "terraclips"- I somehow I missed that these existed entirely. Next time I have finances, I'm going to pick up a set or two, they look like a great idea.
Along with what everyone else said, the Dwarven Forge tiles just have a solid, "3-d" look that I think will have a visual appeal and immersion factor beyond pure prettiness, though there is no denying they will have their limitations.
Just 5K short of a few free wall pieces with windows now. It may be a little silly, but I think having a couple of those will help the utility of the sets a great deal.
It's looking more and more like they are going to hit the $1,000,000 mark (at least) before the KS ends. I am stoked about the $1 mil free reward (treasure piles), but I am almost afraid that "dungeon dressing" add-on pack is going to tempt me to start forking out for add-on packs. The cost of the packs themselves are pretty reasonable, but if you are outside of the US, the additional shipping is pretty harsh.